A Modified Intertrochanteric Osteotomy In Total Hip Arthroplasty For Severe Developmental Dysplasia Of The Hip

Background Total hip arthroplasty (THA) is an effective procedure in the presence of developmental dysplasia of hip (DDH) providing a high rate of functional improvement and pain relief. However, for patients with severe DDH (reaching Crowe type 4 criteria) this procedure can be technically challenging. Yielding the most durable results of THA in patients with DDH is based on restoring the anatomic centre of hip rotation. Hip reduction may require femoral shortening osteotomy to minimize the risk of damage of neurovascular structure caused by excessive limbs lengthening. Various femur osteotomy procedures have been used for hip reduction, including step-cut osteotomy, double chevron osteotomy, and have been proved effectiveness. These techniques, nevertheless, are along with the disadvantages of increasing nonunion and infection rate. So it is beneficial for both patients and medical resources to find an adequate technique for femoral shortening procedure.Purpose This study is to assess the efficacy of a modified intertrochanteric osteotomy technique introduced by Paavilainen used for hip reduction in THA for patients with Crowe type 4 DDH.Method Retrospective reviewed 19 patients (21 hips) from January 2009 to December 2015 who underwent THA for patients with Crowe type 4 DDH in orthopaedics department, QILU hospital. These patients were including 4 Males and 15 Females. In male 1 case was involving bilateral hips and 1 in female, respectively.15 patients were result from dysplasia and 4 were result from infections in childrenhood. The average age was 48.5 (range,29 to 66) years. The clinical outcome was evaluated by comparing the Harris hip scores obtained before operations and at follow-ups. Meanwhile, the anterior-posterior pelvic and hip view radiographs were collected. The following parameters were assessed: radiolucent lines, osteolysis, heterotopic ossification, cortical changes (atrophy or hypertrophy), stem position and subsidence, cup migration or change in inclination, and implant loosening. The leg length discrepancy before and post operation as well as neurovascular complications were also noted.Results The mean follow-up period of all 19 patients is 31 months (range,7 to 69 months). At follow-ups, all patients reported significant pain relief and functional improvement. The mean Harris hip scores significant increased from 55.0 (range,28 to 61) preoperatively to 88.4 (range,78 to 94; P<0.01) postoperatively. No infection, dislocation or loosening of prosthesis was reported by the final follow-up. None of the patients experienced nonunion. Bone union took an average of 3.3 months (range,3 to 6 months).17 patients were suffering from unilateral hip dislocation, and 15 of which received follow-up at 12th month after operations. The average preoperative leg length discrepancy (LLD) in patients was 53.9 mm (range,23 to 76 mm). The average leg length discrepancy immediately after finishing the operations was 9.5 mm (range,4 to 23 mm). At the follow-up of 12th month, the leg length discrepancy was less than 10 mm in 11 patients, between 10 and 20 mm in 3 patients, and more than 20 mm in 1 patient, with a mean discrepancy of 6.9 (range,0 to 21) mm. During the follow up period none of the patients experienced any obvious symptoms of sciatic nerve palsy.Conclusion The modified intertrochanteric osteotomy combined with THA is an effective treatment for Crowe type 4 DDH with short-term follow-up. It is worth to be reserved for surgeons with a special interest in this field and further developed.